Nestling deep in the Kent countryside amid fields of runner beans, artichokes and rhubarb lies the cluster of smart, modern buildings that make up Sandwich technology school. They gleam in the morning sun. But it hasn't always been this way. Until six months ago, many of the school buildings weren't much more than wooden huts. This is just one aspect of the massive transformation the school has undergone over the past eight years, largely due to the passion and energy of its headteacher, Richard Wallis, whose dedication has earned him the RAF award for headteacher of the year in a secondary school.

"I forgot you were coming, otherwise I'd have dressed up," Wallis says. He looks relaxed in a dark suit and white shirt, but his tie is emblazoned with suns and sailing boats. His PA says this is a modest choice for him. He agrees, with a wide smile: "I'm terrible. I am absolutely terrible."

In his large, orderly office, Wallis talks enthusiastically about his love of sailing, how he races at top level, how his desire to share his enjoyment led him into teaching. But when it comes to concentrating on his achievements at the school, his tone falters: "I like the focus to be on the youngsters, students, learning. It's mildly uncomfortable when I'm the focus ... suddenly the limelight has come on to me and I think, no, it's just been a sensational team of people that has done wonders."

Wallis originally trained to be an accountant, but a few months into his first job he realised that he really wanted to teach. He taught sailing at an outreach education centre in East Sussex before going on to become head of the science faculty, then head of upper school, at Downs school in Dartford (now Leigh city technology college). A spell as deputy head at Hugh Christie technology college in Tonbridge followed, then the post came up at Sandwich. He was so excited by the challenge that he took a drop in salary.

Over the eight years Wallis has been in post, the school's results have been steadily improving and in the last cohort, 550 pupils applied for 240 places. Major building works have been undertaken, including a new restaurant, two science labs, an open learning centre, a creative technology suite, and the UK's first in-school cinema. Fundraising and networking come naturally to him - in total, he raised £7m to fund the improvements, and through his contacts secured Boy George to open the creative technology suite and Brenda Blethyn to open the cinema.

He says he is passionate about making a difference in a rural area often overlooked by the government's urban agenda, but stresses that there is more to achievement than getting the grades. "Academic achievement is hugely important, that's what will help to give these youngsters a choice ... also hugely important are the arts, music, sport, how we relate to each other, interpersonal skills, emotional intelligence."

"He's looking to change the culture," says the assistant headteacher, Patrick Couch, who nominated Wallis for the award. "So, for example, all our leavers in year 13 last year got university places. This is a big change for what is basically a high school serving lots of villages, which have some major problems because of the loss of the coal mines and the like."

Much of the inspiration for these changes comes from an international outlook. Wallis has forged links with schools in Singapore, Australia and the US, and is planning a visit to China. He is often asked to speak at seminars and conferences, both nationally and internationally.

Wallis works hard at making connections closer to home, too. During his time at Sandwich, he has been acting director and is now executive director of the Kent Leadership Innovation Centre (Klic); he is a member of the Kent ICT strategic group, and executive headteacher at Montgomery school in Canterbury.

He is also working on a collaboration with Microsoft and with the National College for School Leadership, sharing best practice. Although he enjoys this aspect of the job, when he was spending a lot of time away from the school setting up Klic, he was "astounded at how much I missed the students; they bring a buzz to things".

Wallis lives with his wife in Dartford, in north Kent, where he grew up. Dartford is 55 miles from Sandwich; I wonder how he copes with the long daily journey on top of such an all-consuming job: "I'm not a good role model. I normally leave home around 6.30am and it's not unusual for me to get home at 9pm. It is a long day and I do run out of steam."

But come Friday, he leaves school at 5.30pm and, along with his wife and dog, drives to his boat in Portsmouth. This is a key part of what keeps him grounded. "Sailing or walking the dog is time to think," he says. "I'm a very simple soul, really; I get a huge amount of pleasure from nature."

On a tour of the school, the pupils seem genuinely pleased to see their headteacher striding through the corridors. The school chef talks enthusiastically about his new kitchen, and the food he and his staff produce from it. Staff exchange friendly banter with their head, and are keen to sing his praises. Kim Gillies, an instructor in thedesign and technology department, has been at the school for nine years: "I've seen the change he has made to the school. It's just so good."

Plasma screens and rows of computers fill the classrooms. In fact, the school has more computers than pupils - the place practically sizzles with technology. However, Wallis is quick to point out that it is important not to be impressed by the number of computers and whiteboards; it's how they are used as a learning tool, how they have made learning easier, that matters.

Wallis's reputation as an innovator means he is a man in demand. He has been headhunted more than once, but has never been tempted to jump ship. Though he is pleased with the difference he and the staff have made to the school, he does not feel the job is finished yet and, anyway, it is the children who motivate him: "It's cheesy but it's true: I can make the difference to young people's minds."

RAF award for secondary headteacher of the year

The judges say: "Richard Wallis provides outstanding leadership to the school through the clarity of his vision, values and principles that pervade every aspect of the school's work and are exemplified in the school's motto, 'Learning is at the heart of all we do'."